DaystoPatch

GitLabExploited incident

GitLab CI Lint API server-side request forgery by unauthorized external users (2021)

CVE-2021-39935Medium, CVSS 6.8In CISA's Known Exploited Vulnerabilities catalog since 3 Feb 2026

  • Exploited after a fix existed
FixedFixed for every supported version on the day it became public.

Response

Silence
same day
First public report to first vendor statement
Exposure
same day
First public report to first fix
Follow-through
same day
First public report to a fix for every supported version
  • Vendor silent
  • Vendor statement, no fix
  • Fixed for some versions
  • Fixed when disclosed
  • Date only, no time of day

Timeline and evidence

Open a moment to see its source and archived quote.

  1. First public report

    date only

    GitLab Security Release: 14.5.2, 14.4.4, and 14.3.6 (Dec 6, 2021; Wayback snapshot)CuratedQuote verified

    An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.5 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. Unauthorized external users could perform Server Side Requests via the CI Lint API.

    Coordinated disclosure: the security release post dated Dec 6, 2021 was the first public signal; exploitation was only reported years later (KEV listing 2026-02-03).

    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:4271930e7507d06d…
    Used in metrics
    Yes
    Dispute this timestamp
    3 more sources for this moment
    CVE.org record CVE-2021-39935ClaimedQuote verified13 Dec 2021, 15:47 UTC

    An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.5 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2.

    CVE record published.

    Recorded time
    Precision
    To the minute
    Origin
    Claimed. The date the source gives.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:65ffd12e6645e0f1…
    Used in metrics
    No, kept for the record
    Dispute this timestamp
    Bluesky postClaimedQuote not checked yet12 Mar 2025, 21:01 UTC

    CVE-2021-39935 has confirmed exploit code according to the following sources: Vulncheck KEV.

    Earliest third-party post we hold.

    Source
    Bluesky post social
    Recorded time
    Precision
    To the minute
    Origin
    Claimed. The date the source gives.
    Quote check
    Not checked yet
    Snapshot
    No archived snapshot
    Used in metrics
    No, kept for the record
    Dispute this timestamp
    CISA KEV (CVE-2021-39935)ClaimedQuote verified3 Feb 2026

    GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability

    Added to CISA's KEV catalog on 2026-02-03.

    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Claimed. The date the source gives.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:ef8fffede5c47200…
    Used in metrics
    No, kept for the record
    Dispute this timestamp

  2. Vendor statement

    date onlysame day

    GitLab Security Release: 14.5.2, 14.4.4, and 14.3.6 (Dec 6, 2021; Wayback snapshot)CuratedQuote verified

    Today we are releasing versions 14.5.2, 14.4.4, and 14.3.6 for GitLab Community Edition (CE) and Enterprise Edition (EE).

    Post header reads 'Dec 6, 2021'; the snapshot was captured 2021-12-06 23:51 UTC.

    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:4271930e7507d06d…
    Used in metrics
    Yes
    Dispute this timestamp

  3. First workaround

    No official mitigation found yet.

  4. First fix

    date onlysame day

    GitLab Security Release: 14.5.2, 14.4.4, and 14.3.6 (Dec 6, 2021; Wayback snapshot)CuratedQuote verified

    Today we are releasing versions 14.5.2, 14.4.4, and 14.3.6 for GitLab Community Edition (CE) and Enterprise Edition (EE).

    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:4271930e7507d06d…
    Used in metrics
    Yes
    Dispute this timestamp

  5. Fixed for all versions

    date onlysame day

    GitLab Security Release: 14.5.2, 14.4.4, and 14.3.6 (Dec 6, 2021; Wayback snapshot)CuratedQuote verified

    An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.5 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2.

    All three supported branches (14.3, 14.4, 14.5) fixed in the same release.

    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:4271930e7507d06d…
    Used in metrics
    Yes
    Dispute this timestamp

Send this to your boss

No brief for this incident yet. We write one for every open incident and every critical bug exploited before a fix.

Affected products

  • GitLab Community Edition (CE)
  • GitLab Enterprise Edition (EE)
How we built this timeline

Old bug added to KEV long after the fix (KEV 3 Feb 2026). The KEV entry links the original about.gitlab.com post, which now redirects to a docs index, so the Wayback snapshot is cited.

Severity follows GitLab's own CVSS score 6.8 (medium); NVD scores it 7.5.

The fix applies when user registration is limited ('external users that aren't developers shouldn't have access to the CI Lint API').

Related

GitLab report card